<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>iframe 页面无刷新</title>
    <script>
        function go(){
            //所有的变量提前获取
            var url = document.getElementById("url").value;
            document.getElementById("ifram1").src = url;
        }
    </script>
</head>
<body>

<div>
    <p>请输入地址:</p>
    <p>
        <input type="text" id="url">
        <input type="button" value="提交" onclick="go()">
    </p>
</div>

<div>
    <iframe id = "ifram1" style="width: 100%; height: 500px;"></iframe>
</div>

</body>
</html>